Interpretation:
The energy produced (in kilocalories) in 1 second and the consumption of coal and natural gas (in kilogram) are to be calculated.
Concept introduction:
The power derived from the utilization of chemical or physical resources to provide heat and light or to carry out various processes is known as energy. The SI unit of energy is joule.
Unit conversion is a multiple-step process that is used to convert the unit of measurement of a given quantity. It is determined by multiplicaiton with a conversion factor.
The useful energy derived can be calculated by using the equation:
Conversion factor megajoules to joule is
Conversion factor calorie to kilocalorie is
Answer to Problem 44E
Solution:
Explanation of Solution
a) The number of kilocalories produce in 1 s.
The energy produced in one second by the power plant is given as:
The kilocalorie produced in one second is calculated as follows:
First, convert megajoule into joule, then joule into calorie, and then calorie into kilocalorie.
Conversion of megajoule into kilocalorie is as follows:
Therefore, the kilocalorie produced in one second is
b) The amount of energy it consumes in 1 s if its efficiency is 34%.
The total energy consumed in one second is calculated as follows:
The equation used to calculate the total energy consumed is represented as follows:
The total energy produced in one second is
The efficiency of a person is
Conversion of percentage into decimal:
Substitute the values in the given equation:
Or
The energy consumed in MJ is calculated as follows:
Therefore, the energy consumed (in MJ) is
c) The consumption of coal in 1 s if the power plant were coal fired.
The consumption of coal (in kilogram) is calculated as follows:
First, the energy consumed is divided by the heat of combustion of coal. Then, it is converted into kilograms.
Conversion of kilocalorie into kilogram is as follows:
The energy consumed is
The heat of combustion of coal is
Therefore,
Therefore, the consumption of coal (in kilogram) is
d) The consumption of natural gas in 1 s if the power plant were natural gas fired.
The consumption of natural gas (in kilogram) is calculated as follows:
First, the energy consumed is divided by the heat of combustion of natural gas. Then, it is converted into kilograms.
Conversion of kilocalorie into kilogram is as follows:
The energy consumed is
The heat of combustion of natural gas is
Therefore,
Therefore, the consumption of natural gas (in kilogram) is
Want to see more full solutions like this?
Chapter 9 Solutions
Chemistry In Focus
- Which is the least expensive source of energy in kilojoules per dollar: a box of breakfast cereal that weighs 32 ounces and costs $4.23, or a liter of isooctane (density, 0.69 19 g/mL) that costs $0.45? Compare the nutritional value of the cereal with the heat produced by combustion of the isooctane under standard conditions. A 1.0-ounce serving of the cereal provides 130 Calories.arrow_forwardInsoluble PbBr2(s) precipitates when solutions of Pb(NO3)2(aq) and NaBr(aq) are mixed. Pb(NO3)2(aq) + 2 NaBr(aq) PbBr2(s) + 2 NaNO3(aq) rH = ? To measure the enthalpy change, 200. mL. of 0.75 M Pb(NO3)2(aq) and 200. mL of 1.5 M NaBr(aq) are mixed in a coffee-cup calorimeter. The temperature of the mixture rises by 2.44 C. Calculate the enthalpy change for the precipitation of PbBr2(s), in kJ/mol. (Assume the density of the solution is 1.0 g/mL., and its specific heat capacity is 4.2 J/g K.)arrow_forwardThermal Interactions Part 1: In an insulated container, you mix 200. g of water at 80C with 100. g of water at 20C. After mixing, the temperature of the water is 60C. a How much did the temperature of the hot water change? How much did the temperature of the cold water change? Compare the magnitudes (positive values) of these changes. b During the mixing, how did the heat transfer occur: from hot water to cold, or from cold water to hot? c What quantity of heat was transferred from one sample to the other? d How does the quantity of heat transferred to or from the hot-water sample compare with the quantity of heat transferred to or from the cold-water sample? e Knowing these relative quantities of heat, why is the temperature change of the cold water greater than the magnitude of the temperature change of the hot water. f A sample of hot water is mixed with a sample of cold water that has twice its mass. Predict the temperature change of each of the samples. g You mix two samples of water, and one increases by 20C, while the other drops by 60C. Which of the samples has less mass? How do the masses of the two water samples compare? h A 7-g sample of hot water is mixed with a 3-g sample of cold water. How do the temperature changes of the two water samples compare? Part 2: A sample of water is heated from 10C to 50C. Can you calculate the amount of heat added to the water sample that caused this temperature change? If not, what information do you need to perform this calculation? Part 3: Two samples of water are heated from 20C to 60C. One of the samples requires twice as much heat to bring about this temperature change as the other. How do the masses of the two water samples compare? Explain your reasoning.arrow_forward
- 9.82 The specific heat of gold is 0.13 J g-1 K-1 and that of copper is 0.39 J g-1 K-1. Suppose that we heat both a 25-g sample of gold and a 25-g sample of copper to 80C and then drop them into identical beakers containing 100 mL of cold water at 10°C. When each beaker reaches thermal equilibrium, which of the following will be true, and why? (You should not need to calculate the actual temperatures here.) (a) Both beakers will be at the same temperature. (b) The beaker with the copper sample in it will be at a higher temperature. (c) The beaker with the gold sample in it will be at a higher temperaturearrow_forwardWater gas, a mixture of carbon monoxide and hydrogen, is produced by treating carbon (in the form of coke or coal) with steam at high temperatures. (See Study Question 83.) C(s) + H2O(g) CO(g) + H2(g) Not all of the carbon available is converted to water gas since some is burned to provide the heat for the endothermic reaction of carbon and water. What mass of carbon must be burned (to CO2 gas) to provide the energy to convert 1.00 kg of carbon to water gas?arrow_forwardYou drink 350 mL of diet soda that is at a temperature of 5 C. (a) How much energy will your body expend to raise the temperature of this liquid to body temperature (37 C)? Assume that the density and specific heat capacity of diet soda are the same as for water. (b) Compare the value in part (a) with the caloric content of the beverage. (The label says that it has a caloric content of 1 Calorie.) What is the net energy change in your body resulting from drinking this beverage? (1 Calorie = 1000 kcal = 4184 J.) (c) Carry out a comparison similar to that in part (b) for a nondiet beverage whose label indicates a caloric content of 240 Calories.arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningLiving By Chemistry: First Edition TextbookChemistryISBN:9781559539418Author:Angelica StacyPublisher:MAC HIGHERChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning